Dawn Redwood: The Re-emergence of a Living Fossil

The deciduous redwood tree, Metasequoia, was thought to be extinct when a fossil of it was first “discovered” in China by Shigeru Miki in 1941 or so. And now I have one growing almost in my backyard in California.

Part of the reason it was thought to be extinct may have been that it, like so many trees, was hiding in plain sight. The locals in Modaoqui, a village in Sichuan (alternate Szechwan) Province, near the border with Hubei Province, used it as lumber, as people often do with locally available trees. The trees grew wild by streams with birch, chestnut and liquidamber (sweetgum).

Also in 1941, a forester named Kan originally described a grove of “water-
firs” in Sichuan Province. The locals called them that because of their riparian location. Kan was, despite his observational skills, no botanist. He only knew it was something special and new.

In 1944, Wang Zhan, a forestry official in China, came to the grove and sampled the seed. Seeds and cone comparisons are the basis we use to log a new conifer. These proved that Metasequoia was as-yet unknown other than in fossil records.

Fossil record

The tree had been found in abundance in the fossil record. Paleobotanists knew it by the tiny leaves or needles, the size of the letters typed here, found on branchlets. The record was written in stone through middle-northern latitudes worldwide around 65 million years ago, when dinosaurs may have nibbled the foliage. Like bald cypress, this is a deciduous conifer, which is rather rare in itself.

By the way, all of the research and botanical communication was being done against the backdrop of World War II in China. Brave botanists kept up the good work!

Wang Zhan’s seed specimens proved their individuality and their relationship to the sequoia and redwoods. Although there are conflicting reports, one record says Wang Zhan got the seed to grow, then “proved” it was Metasequoia, in 1946. Figuring time to germinate, leaf and attain a seedling height, this sort of makes sense.

Another source says proving the discovery was completed in 1946 by Dr. Xiansu Hu and a colleague, Wan Chun Cheng. A source says professor Cheng sent an expedition to Sichuan Province in 1946 “for a complete study.”

An expedition leads to the common name that stuck

In any event, Dr. Ralph Chaney, a paleontology professor at the University of California, Berkeley planned an expedition in 1948. Money was provided by the San Francisco Chronicle. Milton Silverman, the far-sighted editor, is credited with giving Metasequoia the common name that stuck – dawn redwood. Articles were sent from China detailing the “living fossil.” Imagine finding a living dinosaur! It caught the fancy of readers, and the series of articles was a syndicated hit.

Chaney and associates met with Dr. Hu. The group sampled three of the more than 6,000 trees. Seed collected by Hu, about one kilo, was divided and sent to botanical gardens and arboreta all over the world in 1949. It’s a good thing, because most of the other Metasequoia in Modaoqui were logged during the Cultural Revolution.

In Oroville, California, where I live, a specimen is growing in back of the Chinese Temple. It is one of the largest I have seen, measuring 48 inches DBH (diameter at breast height) and 69 feet tall.

That this is one of the first few trees of its kind that has borne cones in North America in millions of years is amazing. It must have been one of the first planted of that early seed collection, and at first been a well-cared-for tree. It is located close to a levy and right in the water table for the Feather River. Call it a dawn redwood if you will. It has water-fir credibility.

Sources

This article contains some information gleaned from the Arnold Arboretum, Hoyt Arboretum and Morton Arboretum websites.

John O’Shea, aka Jack, is a Board Certified Master Arborist (BCMA) and Certified Treecare Safety Professional (CTSP). He has taught line-clearance arborists essential skills for the past four years in California, and currently works at The Training Place at Butte College in Oroville, training line-clearance arborists and line pre-inspectors.